As a printing apparatus for executing printing in compliance with printing control data received from a host computer, JP-A-11-78168 discloses a printing apparatus, which incorporates a function of disregarding a printing condition setting command received when the command is not a command that a user requests. This is for preventing inconvenience from occurring, by which the printing condition setting command (printing control data) inputted by the user using a keyboard is changed by the printing condition setting command from the host computer.